Walter Gautschi (December 11, 1927) is a Swiss-American mathematician, known for his contributions to numerical analysis. He has authored over 150 papers in his area and published two books.
Born in Basel, he has a Ph.D. in mathematics from the University of Basel on the thesis Analyse graphischer Integrationsmethoden advised by Alexander Ostrowski and Andreas Speiser (1953). Since then, he did postdoctoral work as a Janggen-Pöhn Research Fellow at the Istituto Nazionale per le Applicazioni del Calcolo in Rome (1954) and at the Harvard Computation Laboratory (1955). He had positions at National Bureau of Standards (1956–59), the American University in Washington D.C., the Oak Ridge National Laboratory (1959–63) before joining Purdue University where he has worked since (1963-2000) and now being professor emeritus. Visiting, he has been Fulbright Scholar at the Technical University of Munich (1970), University of Wisconsin–Madison (1976), Argonne National Laboratory, the Wright-Patterson Air Force Base, ETH Zurich (1996-2001), the University of Padova (1997), and the University of Basel (2000).
- Colloquium approximatietheorie, MC Syllabus 14, Mathematisch Centrum Amsterdam, 1971. With H. Bavinck and G. M. Willems
- Numerical analysis: an introduction, Birkhäuser, Boston, 1997
- Orthogonal polynomials: computation and approximation, Oxford University Press, Oxford, 2004.